435
FXUS65 KBYZ 161142
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
542 AM MDT WED SEP 16 2026
KEY MESSAGES
- INCREASING PRECIPITATION CHANCES THURSDAY THROUGH THE WEEKEND.
LOCALLY HEAVY RAINFALL POSSIBLE FRIDAY INTO SATURDAY. HEADS UP
TO THOSE WITH OUTDOOR PLANS.
- STRONG THUNDERSTORMS POSSIBLE FRIDAY EAST OF BILLINGS.
DISCUSSION
THROUGH NEXT TUESDAY...
SATELLITE IMAGERY SHOWS A TROF DIGGING THRU WA/OR, WHILE THE WEAK
NORTHERN SPLIT PORTION OF THE TROF SKIRTS ACROSS SOUTHERN CANADA.
WE WON'T SEE PRECIP OVER THE NEXT 24 HOURS, BUT THE WAVE TO OUR
NORTH WILL ALLOW FOR A REINFORCING PUSH OF COOLER CANADIAN AIR
STARTING WITH A FRONTAL PASSAGE EARLY TODAY (SHIFTING WINDS FROM
S-SW TO NW-N). SURFACE WINDS WILL VEER TO THE NE-E LATE TODAY AND
TONIGHT. SOMETHING TO WATCH IS A RISK OF FOG IN OUR EAST LATE
TONIGHT INTO EARLY THURSDAY.
RETURN FLOW TONIGHT AND THURSDAY WILL DRIVE PWATS BACK UP TO
ANOMALOUS LEVELS, IN EXCESS OF AN INCH OVER THE EAST. THE HIGH
MOISTURE CONTENT WILL REMAIN IN PLACE INTO THE WEEKEND AS WE AWAIT
THE SLOW-MOVING LOW TO OUR WEST. CHANCE OF SHOWERS WILL INCREASE
THURSDAY IN TWO AREAS, OUR WEST PER THE APPROACHING LOW, AND IN
FAR SOUTHEAST MT AS A WEAK MONSOONAL WAVE LIFTS OUT OF THE SW
CONUS AND THRU EASTERN WY. PERIODS OF SHOWERS AND SOME EMBEDDED
T-STORMS ARE EXPECTED FRIDAY AND SATURDAY AS THE LOW TRACKS IN
SOME FASHION THROUGH ID/WY/MT, EVENTUALLY EXITING TO THE EAST
SUNDAY. WEAK FLOW ALOFT THROUGH THIS PERIOD OF TIME IS A REASON
FOR MODEL UNCERTAINTY, AND THE ENSEMBLE RANGES IN POTENTIAL QPF
SHOW VERY HIGH SPREAD. GENERALLY SPEAKING, FROM FRIDAY THRU
SATURDAY NIGHT, THERE IS A GREATER THAN 50% CHANCE OF A HALF INCH
OF RAIN ACROSS MOST OF THE FORECAST AREA. HIGHEST PROBS FOR AN
INCH OF RAIN ARE IN OUR NORTHEAST, WHICH MAKES SENSE GIVEN THE
HIGH PWATS TO OUR EAST AND SOME POTENTIAL FOR DRY SLOTTING
EMERGING FROM NORTHERN WY. THIS WILL BE A SEASONABLY WARM SYSTEM
WITH ABOVE NORMAL HEIGHTS PERSISTING. LOOK FOR SNOW LEVELS TO STAY
ABOVE 10KFT EVEN UNDER THE UPPER LOW ITSELF ON SUNDAY. REGARDING
SEVERE POTENTIAL, BULK SHEAR WILL REMAIN WEAK BUT IF THERE IS AN
OPPORTUNITY FOR STRONG STORMS IT SEEMS TO BE FRIDAY WHEN
INSTABILITY WILL BE HIGHEST AND LOW LEVEL WINDS REMAIN EASTERLY.
SOMETHING TO WATCH.
LATEST MODELS HAVE TRENDED A BIT SLOWER WITH THE DEPARTURE OF THE
LOW, AND THUS SHOWERS WILL LIKELY LINGER IN OUR EAST INTO SUNDAY.
ENSEMBLE CONSENSUS IS FOR RIDGING TO REESTABLISH ITSELF EARLY NEXT
WEEK LEADING TO A WARMER AND DRY MONDAY/TUESDAY...BUT IT IS ALSO
POSSIBLE THAT THE RIDGE BEGINS TO BREAK DOWN AGAIN BY THE MIDDLE
OF NEXT WEEK. HIGH UNCERTAINTY HERE.
COOLER THAN NORMAL TEMPS TODAY SHOULD WARM TO NEAR NORMAL THURSDAY
AND A LITTLE ABOVE NORMAL FRIDAY (THE WARMEST DAY OF THE WEEK W/
MID 70S TO LOWER 80S). THERE WILL BE SOME MAGNITUDE OF COOLING FOR
THE WEEKEND (MID 60S TO MID 70S) BEFORE TEMPS RISE BACK TO THE
MID 70S TO LOWER 80S MONDAY/TUESDAY. OVERALL NOTHING EXTREME
EITHER WAY.
JKL
AVIATION
A WEAK FRONTAL PASSAGE IS EXPECTED TO SHIFT WINDS NORTHWEST
THROUGH THE MORNING THEN NORTHEAST THROUGH THE AFTERNOON. THERE IS
ABOUT A 20% CHANCE FOR FOG TO DEVELOP THURSDAY MORNING ACROSS
SOUTHEAST MT (KMLS, KBHK, K97M). TS
PRELIMINARY POINT TEMP/POPS
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 070 045/075 054/078 054/070 051/072 049/076 050/074
0/U 00/E 16/T 97/T 63/W 10/U 01/B
LVM 072 043/076 049/075 046/069 045/073 045/077 046/075
0/U 03/W 28/T 97/T 41/B 00/U 01/U
HDN 071 044/078 051/080 051/070 047/072 044/078 043/076
0/U 00/E 14/T +8/T 74/W 10/U 00/U
MLS 071 044/076 056/080 054/069 050/069 048/074 049/074
0/U 01/E 12/T 99/T 75/T 20/U 00/U
4BQ 074 047/075 057/080 055/070 051/070 048/075 049/076
0/U 04/W 32/T 98/T 75/T 31/B 01/U
BHK 076 039/072 050/078 049/069 046/069 043/073 044/076
1/U 02/W 31/B 78/T 76/T 22/W 00/U
SHR 072 042/075 049/078 048/069 044/071 041/076 042/077
0/U 03/W 16/T 99/T 74/W 21/U 01/U
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page